Weather and Climate

CLIMATE

Rainfall. Although the Highlands give the impression of verdant bounty, and although the average rainfall (700 mill/p.a.) is certainly higher than further inland, the region has always suffered from the extremes of the harsh Australian environment. The earliest settlers found out from the aborigines that the rivers alternated between flood and drought. (Floods on the Wingecarribee were common until about 30 years ago when the weir was built.) The greenness of the countryside soon changes to olive drab during drought - some of which may last years (El Nino or not). The countryside in summer is always dryer as higher temeratures cause increased evaporation. Average Rainfall (in Mms.) Clockwise from left - Fitzroy Falls: the falls, escarpment, weir. Catchment Area. Although there seem to be more rivers and creeks than other parts of the countryside, these do not always run (dams or no dams). Most water is in fact subterranean - like much of Australia. That is why creeks sometimes seem to rise out of nowhere, and water seems to flow from out of the escarpments even when there is no rain. The many dams on farms indicate the need for conserving water. Being on the Great Dividing Range the Highlands receives heavier precipitation on the escarpments - those to the east contain sub-tropical rainforests - and the run-off to the Wollondilly River in the west, the Nepean to the north, and the Shoalhaven to the south feeds into the water supplies for Sydney and the South Coast. Micro-climates. The Highlands has a land area almost as big as the city of Sydney, so it is not surprising it contains many micro-climates. The local weather station (see Weather Forecast - above) is at Moss Vale and conditions there can often be different to the prevailing winds, rainfall and temperature just 5 to 10 kilometres away. However, it gives a general overview of local conditions. Precipitation (rainfall and fogs) is always heavier north of Mittagong and to the east around Robertson and Fitzroy Falls. The air temperature and wind chill factor can vary throughout the Highlands on any given day. Bushfires. Surrounded as it is by 100s of kilometres of bushland, the Highlands can have frequent bushfires. Some of these are deliberately lit or due to neglect of campfires. Most, as recent satellite research has been able to prove, are caused by lightning strikes during storms. Many local native species of plants need fire for propagation and explains why revegetation is swift after fire. Periodic burning off of the undergrowth helps to maintain the bush. But visitors should never light campfires in any other than designated fireplaces, and never during bushfire alert periods! Clockwise from top left - rainforest at Robertson, view over coast, grazing land at Wildes Meadow, river flat at Bong Bong. Average Temperatures - Degrees Celsius Temperature. Europeans, by and large, made pretty good colonists in other parts of the globe: they were able to adjust to very different climates and survive. However, they still retained deep subconscious links with the cool climate of their homeland. Wherever they were, the English - come the first heat of summer - headed for the hills (if they could afford it). The Highlands were a popular destination in summer up to the mid C20th. Now airconditioning is common, people like to come in winter to sit by a cosy fire! Four distinct seasons. In most of mainland Australia there seems to be two distinct seasons: when it's hot, and when it's not (summer and winter!) In many places 'when it's not' is only a few months of the year. The Highlands has four distinct seasons, clearly heralded not only by changes in the climate, but by the changes in the many European trees, shrubs and flowers widely planted throughout the district. Summer is cooler than the coast (average temperatures from 15 to the mid 20s Celsius) - up to 10 degrees cooler. But being Australia, this does not mean that there can't be days in the 30s, or during a heatwave, over 40! Spring and Autumn are markedly cooler. Winter temperatures are typically in the high teens down to freezing. Heavy frosts are common, and from time to time it snows. Part of the attraction of the Highlands are its seasonal changes - which has made it a popular destination for visitors year round since the 19th century. Clockwise from top left - Summer picnics at Penrose; autumn colour at Moidart, Burradoo; winter snow on the ranges; spring gardens at Mittagong.